Field of the Invention
The present invention relates to a sheet conveying apparatus that performs skew feeding correction on a sheet, and an image forming apparatus including the same.
Description of the Related Art
There has been a disclosed conventional technology which butts a head of a sheet against a nip portion of a pair of registration rollers, rotation of which is suspended, to form a loop, and performs skew feeding correction on the sheet (Japanese Patent Laid-Open No. 2000-118801).
However, in the conventional technology, while a head side of the sheet in a conveying direction is subjected to skew feeding correction, a tail side of the sheet in the conveying direction remains in a skew feeding position. Thus, torsion is generated in a loop formed between the pair of registration rollers and a pair of upstream rollers. When the sheet continues to be conveyed in this state, a shear force applied to the sheet gradually increases. When the increasing shear force exceeds rigidity of the sheet, the sheet may kink. Then, there is a concern that a wrinkle may be generated in the sheet when the sheet passes through a nip portion of a pair of downstream registration rollers. This wrinkle is prone to be easily generated in a sheet nipped and conveyed in a long distance by two pairs of rollers that form a loop, or a sheet which easily kinks and has low rigidity. Further, the wrinkle is prone to be noticeably easily generated in an image forming apparatus in which a distance between two pairs of rollers is configured to be short in order to respond to various media such as an envelope whose conveying length is short.